1. Field of the Invention
The present invention generally relates to a resist stripping method and apparatus, and more particularly to a resist stripping method and apparatus which can remove the unnecessary resist from a substrate in a process of a lift-off method.
2. Description of Related Art
A lift-off method is one of the methods in a manufacturing process of semiconductor devices for planarizing a surface of an insulating layer that covers wiring patterns and parts among the wiring patterns on a substrate. In the lift-off method, the wiring patterns are formed on the substrate by etching, or the like, and then the insulating layer with the same thickness as the thickness of the wiring patterns is deposited over the substrate by a method such as a chemical vapor deposition method without removing a resist, which was used as a mask in the etching. Thus, the insulating layer is deposited on the resist and non-resist areas on the substrate, and the areas without the wiring patterns are filled up with the insulating layer. Next, the resist and the insulating layer that is deposited on the resist are stripped, and after that, an insulating layer is further deposited over the substrate. As a result, the insulating layer with a planarized surface can be formed on the substrate on which the wiring patterns are formed.
As described above, the lift-off method requires a process to remove the resist and the insulating layer deposited on the resist. Conventionally, the process is performed by immersing the substrate in stripping solution, which is a chemical solution for removing the resist from the surface of the substrate. However, since the conventional method strips the resist only by a chemical effect of the stripping solution, there are disadvantages in that the method is time consuming, and the resists tend to remain.